Is the universe 2D or 3D?

1 Answer
Dec 21, 2015

It is at least 4D.

Explanation:

The Universe can't be 2D as we live in a 3D world. So, the Universe has at least 3 dimensions.

Einstein's General Theory of Relativity describes the Universe as 4 dimensional space-time.

String Theory, if it is correct, requires the Universe to have up to 26 dimensions.